Hi Alex, I had to sign up just so I could post on your question. First of all, the answer is as much as you can afford without feeling guilty, and screw guilt anyway! Part of the fun of any hobby is the acquisition of new equipment or tools, so buy whatever shiney new object delights you, and then delight in it!

I wanted to say that I was taken aback by how many of the answers you received talked about wives being a limiting factor in how much is spent. I can only surmise that more, way more, men than women have a photography habit. Or maybe the women just aren't on this forum.

I am here to say that women are just as susceptible to GAS, and husbands may indeed be the limiting factor. However, yesterday my husband and I stopped at the camera shop. There were 2 lenses that I was interested in and after playing a bit with them, I definitely wanted them both but decided the prudent thing would be to get one now and the next in a month or 2. My husband stepped up and said, "just go ahead and get them both." So, I was pleased and walked out with the 2 lenses. Later that day he said, "So I'm covered for Valentine's Day, right?" And you know what? He is! i like a different kind of candy!